Stop motion tripper mechanisms for knitting machines



May 5, 1959 v. T. STACK 2,834,775

STOP MOTION TRIPPER MECHANISMS FOR KNITTING MACHINES Filed July 1'7, 195a fiN: $10.23. I

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BY 7 a ATTONE United States Patent STOP MOTION TRIPPER MECHANISMS FOR KNITTING MACHINES Vernon T. Stack, Winston-Salem, N.C., assignor to Hanes Hosiery Mills Company, Winston-Salem, N.C., a corporation of North Carolina Application July 17, 1958, Serial No. 749,248

7 Claims. (Cl. 66-163) This invention relates to stop motion mechanisms for knitting machines. More particularly, this invention relates to stop motion tripper mechanisms for circular knitting machines such, for example, as the well known Scott and Williams model KN hosiery machine equipped with retractable yarn feeds, welting mechanism and clamp and cutter means for severing the yarn upon retraction of a feed. If, in the operation of hosiery machines of a kind referred to, the yarn cutter means should fail to sever a yarn as the feed is retracted, the yarn is apt to enter the clearance interval between the cap and the transfer jacks of the welting mechanism, and either become wrapped about the transfer dial hub or become fouled with the jacks. If this should occur, the accumulation of the wrapped or accumulated yarn may become sufiiciently large to jam the transfer dial and interfere with free movement of the jacks, thereby causing improper make-up or transfer, and may cause the jacks to be broken or bent by the cams which actuate them.

The chief aim of my invention is to obviate the difiiculties above referred to. How this objective is realized in practice will appear from the following detailed description of the attached drawings, whereing:

Fig. 1 is a partially diagrammatic view in perspective showing a conventional welting mechanism and yarn clamp and cutter means, for a circular knitting machine commonly used in the production of welt top seamless stockings, embodying a preferred form of my invention.

Fig. 2 is a fragmentary sectional view taken as indicated by the angled arrows II-II in Fig. 1.

With specific reference to the drawings, the usual stationary transfer cap of the welting mechanism of the machine is indicated at 1, the usual stationary outer transfer jack actuating cam at 2, the usual radially-slotted transfer dial at 4, the usual transfer jacks at 6, one of the usual retractable yarn feeding fingers at 7, the usual yarn clamp and cutter means at 8 and a conventional, electrically-operable, stop motion control at 9 for actuating the usual clutch tripping lever 10 of the machine. The stop-motion control 9 may be of the type disclosed in Vossen US. Patent No. 2,490,936 granted on December 13, 1949.

The stop motion tripper mechanism with which the present invention is concerned includes a pressure sensitive contact element on finger 11, which may be fashioned from a length of suitably stiff wire. Finger 11 has its outer end 12 bent downwardly and engaged, with capacity for free pivotal movement in a vertical plane, within a hole 13 in the top of the cap 1. The opposite end 14 of the finger 11 is inclined downwardly and extends through a correspondingly inclined clearance aperture 15 in the cap 1 into close proximity to the hub 16 of the dial 4. The distal end 14a of finger 11 is further inclined so as to be substantially vertical, and, it will be noted, is disposed in the interval or space between the transfer cap 1 and transfer dial 4.

Fixedly mounted on the cap 1, with interposition of a "ice block 17 of insulation, is a metallic contact element 18 in the form of a tongue which overlies the finger 11 and which has its inner end spaced by a slight interval from said finger. The outer end of the contact element 18 is bent upwardly as at 20, and to the top end thereof is secured one end of a conductor 21. The other end of conductor 21 is secured to a terminal 22 of the stop motion control 9, as shown in Fig. 1. Both the finger 11 and the contact element 18 are made of electrically conductive metal.

Operation Assume in Fig. 1 that the feed 7 has been retracted that the cutter and clamp means 8 has failed to sever the yarn Y, that the yarn is being dragged in the direction of the arrow by the knitting needle (not shown) last fed, and that the yarn has been dragged into the clearance between the cap 1 and the dial 4. As the yarn encounters the end 14 of the finger 11, as shown in Fig. 2, said finger is lifted vertically into contact with the element 18, as will be readily understood, thereby grounding terminal 22 through conductor 21 and the frame of the knitting machine. As a consequence, the stop motion control 9 is activated in the usual manner to trip the clutch lever 10 and stop the machine, the yarn thereby being prevented from wrapping about the hub 16 of the dial 4 or fouling the jacks 6. In this way, accumulation of yarn in the interval between the cap 1 and the dial 4 is effectively precluded, and the possibility of jamming of or injury to the transfer jacks is prevented.

It is to be noted that the distal end 14a of the finger 11 may be disposed at any desired point between the cap 1 and the dial 4. For example, the distal end 14a of the finger 11 may be disposed above the jacks 6 immediately behind the stationary cam 2, so that as soon as the yarn underpasses the cam 2 it will contact the finger 11 to trip the stop motion control.

The stop motion tripper mechanism of this invention, of course, is readily adaptable for use in connection with all types of circular knitting machines. For example, it is readily adaptable for use in connection with a machine having the yarn clamp and cutter mechanism disclosed in Stack US. Patent No. 2,824,436, granted February 25, 1958.

While a preferred embodiment of this invention has been disclosed and described in detail, it will be obvious to one skilled in the art that various modifications may be made therein without departing from the invention as hereinafter claimed.

Having thus described my invention, I claim:

1. A stop motion tripper mechanism for a circular knitting machine having a transfer cap, a transfer dial spaced from the cap and a stop motion control, said mechanism including an element sensitive to yarn pressure disposed within the interval between the cap and the dial; a contact element adjacent the pressure sensitive element; and an electric conductor connecting the contact element to the stop motion control.

2. A stop motion tripper mechanism according to claim 1 wherein the yarn pressure sensitive element is adapted to engage the contact element and thereby activate the stop motion control.

3. A stop motion tripper mechanism according to claim 2 wherein the yarn pressure sensitive element is adapted to be activated to engage the contact element by yarn passing betwen the cap and dial.

4. A stop motion tripper mechanism according to claim 1 wherein the yarn pressure sensitive element is pivotally supported by the transfer cap with capacity for pivotal displacement to engage the contact element and thereby activate the stop motion control.

5. A stop motion tripper mechanism according to claim 4 wherein the yarn pressure sensitive element is adapted sesame to be activated to engage the contact element by yarn passing between the cap and dial.

6. A stop motion tripper mechanism according to claim 1 wherein the yarn pressure sensitive element is in the form of a finger freely pivoted for vertical movement, wherein the pressure sensitive element is adapted to be displaced vertically upon passage of yarn between the dial and the cap and thereby engage the contact element to activate the stop motion control.

7. A stop motion tripper mechanism for a circular knitting machine having a transfer cap, a transfer dial spaced from the cap and a stop motion control, said mechanism including an element sensitive to yarn pressure movably supported by the cap and reaching down into the interval between the cap and the dial; a cooperating contact element adjacent the yarn pressure sensitive element; and an electric conductor connecting the contact element to a terminal of the stop motion control whereby, in the event yarn passes between the dial and the cap, the yarn pressure sensitive element is moved by the yarn into engagement with the contact element to 10 thereby activate the stop motion control.

No references cited. 

